Gametrailers.com have given us an 10 minute extended look at the technical improvements of TR: Definitive Edition. Check it out at the link below (don't believe we can embed their vids here?):

Technical Improvements Walkthrough

GamesRadar also gives us over an our of TR: DE footage below, as well as confirming that the PS4 version runs at 60fps:

GamesRadar - Tomb Raider: Definitive Edition